Move UBSan warnings from a blacklist to the source

webrtc/rtc_base/random_unittest.cc

Index: webrtc/rtc_base/random_unittest.cc
diff --git a/webrtc/rtc_base/random_unittest.cc b/webrtc/rtc_base/random_unittest.cc
index 0af2733faaca1c2bfa625ad9c3258077dee3d34a..12d17ad3404e609efed9d51b369fbd3e1076210f 100644
--- a/webrtc/rtc_base/random_unittest.cc
+++ b/webrtc/rtc_base/random_unittest.cc
@@ -199,13 +199,7 @@ TEST(RandomNumberGeneratorTest, UniformUnsignedInterval) {
   BucketTestUnsignedInterval(1000, 1000000, 0, 2147483999, 4, &prng);
 }
 
-// Disabled for UBSan: https://bugs.chromium.org/p/webrtc/issues/detail?id=5491
-#ifdef UNDEFINED_SANITIZER
-#define MAYBE_UniformSignedInterval DISABLED_UniformSignedInterval
-#else
-#define MAYBE_UniformSignedInterval UniformSignedInterval
-#endif
-TEST(RandomNumberGeneratorTest, MAYBE_UniformSignedInterval) {
+TEST(RandomNumberGeneratorTest, UniformSignedInterval) {
   Random prng(66260695729ull);
   BucketTestSignedInterval(2, 100000, 0, 1, 3, &prng);
   BucketTestSignedInterval(7, 100000, -2, 4, 3, &prng);